Carburetor



C. J. ERADE CARBURETOR Filed May 29, 1931 2 Sheets-Sheet 2 fizuerzfar' dfrade Patented Oct. 3, 1933 UN TE STAT ATENTOF 'I Y "1 ,928,97 l' I i CARBURETOR o H Charles Julien Erade, Brussels, Belgium Application May 29, 1931, Serial No. 541,054,

' and in Belgium June 17,1930

4 m (o1. sci- 49) My invention relates to a carburetor for'intemal combustion engines, particularly those employed on motor vehicles, which permits the most suitable 'mixture of air and fuel to be obtained automatically for all working con ditions of the engine, and also permits a rapid acceleration to be obtained whatever be its speedorits load. p 7 '7 f For this purpose means have been provided in order to'obtain automatically in a carburetor the preferred mixture curve or a curve approaching it, forexample that which indicates arich mixture for small andlarge openings'ofjthe carburetor, and a less rich ,or economical mixture at mean openings of the carburetor, thatisto say those mostjempioyed in the case ofa motor vehicle.

- With a view to obtaining this result a constant level carburetorhas been provided, combining opening or closing means controlling different orifices forthe admission of air, fuel, and the outlet of the gases simultaneously and in the required portions, in order to supply 'the engine with the most suitable mixture asregards quality and quantity, whatever be its working conditions. h

.According to the invention, the carburetor is formed bya main cylindrical duct in iwhichfare providedtwo butterfiyvalves; one for regulating the air admission and the other for regulating the delivery of the gases. .Two ducts open out towards the cent-re of the main duct, the lower one 'of these ducts "comprising a fuel admission jet, and the'uper of these two ducts serving for the admission of additional airy-and through which a part of the air drawn in by the engine is directed so as to produce'a restraining action on the delivery-of fuelsupplied by the jet. The "delivery of fuel is proportionaljto the vacuum existing in the carburetor and resulting from the suction which is a function of the speed of the engine., p

The speed of an engine can increase under two conditions of working either' under constant load by an increase in the degree of opening of the carburetor throttle, or by a reduction on the load on the engine, the degree of the throttle valve remaining constant; Consequentlyy' the carburetor requires two combinations for the fuel, the first for the variable opening of the throttleand the second for the'constant aperture of the throttle.

In the case of very wide limits of speed of the engine, a variable jet has also been provided, the progressive openingof which is combined with that of the throttle valves orclosing mem ber's'controlling the air admission or gas outlet orifices. w v The'carburetor also permits the petrol supplied to becompletely restrainedif desired by a suitable combination of thefcontrol of the opening; of the levers admitting restraining air and gas in order to stop the delivery of the carburetor so as to utilize the engine as a brake forthevehicle when going downhill "without consuming fuel. i o 1 Some'forms" of constructionofthesubject of the invention are illustrated hereinafter simply by wayof example with reference to the accompanying drawings, in "which: a Figure 1 is a diagrammatic view of a carburetor showingtwo throttle valves provided in the main ductandcomprising arestraining air duct having an adjustable aperture. V H 1 Figure 2 is a diagrammatic view s imilar'to Figure 1 but comprising an adjustable needle valvein the duct." H l Figure 3 is'a sectirmal viewof the form of construction shown in'Figure l. Figure A is afsectional: view taken on'the line 91 -4 of Figure I 3, showing the construction of-theregulating member controlling theorifice admitting restraining air. 1 V Figure 5 is a detail view of the adjustable needle valve controlling the orifice of the duct whenthe carburetor is constructed according to the embodiment shown diagrammatically in Fauna, n h V Figure. 6 is a cross sectional detail view of a restraining air duct according to one embodiment ofthe invention. g "Figure '7 is a side ,elevationof the same. As shown in the drawings, the carburetor is formed by a tubular bodyf40 having a flange 41 for attachmentto the engine'., This tubular body is provided with two flaps or throttle valves. 42 and 43 providedrespectively for regulating theadmission of noncarbureted air, and the v outlet of the gases, the said flaps or throttle valves being connected-together by means of a connection44 pivoted on the one hand at 45 to the lever 46 of the valve42, and on the other hand at 47'tof the leverof handle the valve 43 (Figure 1); V o V In the-interior and aproximately at the center of the tubular body 40 enters aduct-49-provided 48 controlling with a jet 5 0 for the admission of the fuel, this over the end or the said jet and comprising an orifice-52 'for the passage of the restraining air admitted through a lateral nozzle 53 provided in the mass of the main body 40, and

preferably entering above and at the level of mains constant, but the section of passage of the auxiliary nozzle 53 is controlled by a flap or rotary cock 60 connected by the levers 61";and.

62 and the connection 63 to the control handle 48 of the throttle valve 43.

As shown in Figure 5, the aperture of'the duct 53 is constant but the calibratedorif lce of the jet is controlled by a movable and adjustable.

needle valve 64 mounted to slide vertically in a collar 51a in the. duct 51; this needlev valve is controlled by means .of'the handle ,48 through the'levers 65, 66 and 67. Finally, in the formof construction shown i Figure. 2, the carburetor comprises the whole of the adjusting devices.

' In 'the above description and, construction of the different members comprising the'carburetor forming the subject of the invention, it will be understood that by a judiciousand proportional adjustment of the 'air and the 'fueladmission and gas outlet apertures, it is easy to obtain at all timesjthe mostfavourable mixture for the difierent conditions of work of the engine.

The vacuum and consequently the delivery of fuel in, the mixture chamber depend upon the aperturelof the throttle 43 .through which the gases pass outand of the. throttle 42 admitting the main air so that the aperture of these throttleswill. be regulated in such a way that the vacuumwill besufficient to. permit the necessary delivery of petrol from the jet. "The relative apertures of the two throttles'areregulated by the length of' the corresponding levers 46fand 18 of the throttle 'valves 42. and 43- connected together. by the jointed connection 44..

Z In order'to obtain the, economical mixture for medium openings of the gas outlet throttle valve 43,- the admission of restraining air through the duct 53, 51 will be regulated and this air will act by pressure according to its speed upon the delivery of the jet .50. The adjustmentof'restraining airis effected by means of the-cock controlled by the lever 61 connectedsby the pivoted. connection 63 to the .lever 62. of @the gas outlet throttle valve 43, the said lever being rig'id with the control lever 48.- Thelengthan'd" the arrangement of the control levers 61 and62. will be regulated in such a way as to produoe the restrainingfl'action upon the delivery of the jet which will produce an economical mixture for medium'fc'onditions of working of the engine,

and the less intense restraining action which pro- For, this case the arrangement shown in Figures 2 andv 5 ,been provided. in vwhich a movable and adjustable needle valve 64.is,provided for controlling the outlet orifieeor ,the; jet and eonsequently of the fuel delivery. Pivoted levers 65, 66 and 67, suitably arranged and designed, are actuated by the control lever 48 permitting the height of the needle valve to be varied in the aperture of the jet 50, thus varying the section of the outlet passage for the fuel.

This arrangement may be employed in combination with the adjustable admission of restraining air, as shown in Figure 2..

In the embodiment shown in Figs. 6 and '7 the means used for controlling and regulating the inlet aperture of the restraining air duct 51 consist in providing in the top portion of said duct a spindle 68 around which may be rotated a sleeve 69 rigid with a disc 70 furnished with a suitable aperture 71 adapted to register with an aperture .72; machined in the side wall of the duct 51, upon operation of the lever 61 connected by the connection 62 63 to throttle valve 43.

If desired, a removable washer 73 may be interposed between the disc '70 and the duct.body 51 (Fig.6),said washer being provided with an air admitting orifice '74.

This arrangement enables .a ready, fitting of thefwasher having the most suitable restraining airfadmitting orifice.

- As. shown in Figure 6, the cross sectional area of the air' admission orifices is, adjustable by means-of, a cap or cook 92 having. several ports 93,. said cock being formed with an operating lever which may be actuated in any convenient manner.

In all the embodiments hereinbefore described, the delivery orifice 50a of the spray nozzle 50 or the orificethrough which, the fuel is supplied into the mixing chamber may be of conical or crater shape, so as to confine the restrainingair towards the fuel. jet. i Moreover, thecross sectional area between the said orifice 50a of the spray nozzle 50 and the outlet orifice 510 of the restraining air duct 51 may be adjusted inv any. convenient way.

"Finally the carburetor may be provided with any desired number of spray nozzles, one or more of which may be acted upon by restraining air,

lar body at about its center, an upper auxiliary air duct coaxial with the lower duct'and secured to the upper side of the tubularbody, a valve in this upper duct for controlling thepassage of air in this duct, a control member for this valve and a common control for simultaneously varying the admission of air in this auxiliary air duct, the main air admission and the outlet of mixture, means otherthan the said valve in the upper duct. for controlling the volume. of air admitted in said auxiliary air duct, and means for .varying the aperture of the fueladmissionjet.

2. A carburetor for internal combustion-engines comprising a tubular body. having a flange for attachmentto the engine, a first throttle valve in this tubular body for controlling. the main air supply, a second throttle valve in the tubularbody for controlling the outlet of the mixture; a. lower fuel duct connected to the under side of the tubular body at about itscenter, an upperauxiliary air} duct. coaxial with the lower duct and secured to the upper side of the tubular body, a first aperture in this upper duct communicating with the atmosphere, a control member for said aperture, a second aperture in this upper duct, a control 'member for controlling the communication of said second aperture with the atmosphere, said latter control member being connected to a common control for simultaneously varying the admission of auxiliary air, the admission of main air and the outlet of mixture.

3. A carburetor for internal combustion en gines comprising a tubular body having a flange for attachment to the engine, a first throttle valve in this tubular body for controlling themain air supply, a second throttle valve in the tubular body for controlling the outlet of the mixture, a lower fuel duct connected to the under side of the tubular body at about its center, a needle longitudinally displaceable in the fuel admission duct, an upper auxiliary air duct coaxial with the lower duct and secured tothe upper side of the tubular body, a valve in this. upper duct for controlling the passage of air in this duct, a control member for this valve, and a common control for simultaneously varying the admission of air in this auxiliary air duct, the main air admission. and the outlet of mixture, and means for simultaneously displacing the fuel duct control needle with the aforesaid common control.

' 4. A carburetor for attachment ,to the engine, a first throttle valve in this tubular body for controlling the main air supply, a second throttle valve in the tubular body for controlling the outlet of the mixture, 9.

lower fuel duct connected to the under side of the:

CHARLES JULIEN ERADE.

for internal combustion engines comprising a tubular body having a flange 

